x='0123456789'
# x[0]='0' x[1]='1'
# x[2]='2' x[3]='3'
# x[4]='4' x[5]='5'
# x[6]='6' x[7]='7'
# x[8]='8' x[9]='9'
print(x[1:7:2])
print(x[ : :2])
print(x[7:1:-2])
print(x[ : :-1])